摘要:

AbstractThe photoreactions of various halogenated naphthalenes and biphenyls in methanol at 290‐310 nm are affected by addition of heavy‐atom lithium salts. The triplet decay rate appears to be increased relative to the reaction rate resulting in overall rate decrease. The effect of iodide is greater than that of added bromide while the reaction rates in the presence of chloride or in the absence of external heavy atoms proceed in the order of decreasing bond strength of the carbon‐halogen

ISSN:0165-0513    

DOI:10.1002/recl.19770961002

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractCumulenic ethers of the type R′R″C=C=C=CHOMe1(R′, R″ = H, H; H, Me or Me, Me) are readily convertible into 3‐alken‐1‐ynes R′R″C=CR−C≡C−H 2 (R = alkyl or Ph) upon treatment with Grignard reagents, RMgX, in the presence of small amounts of CuBr. Interaction of substrates 1 with homocuprates [RCuR]MgX results generally in mixtures of2and 1‐methoxy‐1,3‐butadienes R′R″C=CRCH=CHOMe3, whereas the adducts3are formed exclusively if heterocuprate

ISSN:0165-0513    

DOI:10.1002/recl.19770961003

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe dianions from a number of α‐sulfonyl ketones have been obtained using sodium hydride and n‐butyllithium. The dianions can produce with carbon disulfide,S‐dimethyl dithiocarbonate or dimethyl trithiocarbonate different addition compounds. The chemical reactions of these compounds with phosphorus pentasulfide, phenylhydrazine and methanol (in acid medium) have been invest

ISSN:0165-0513    

DOI:10.1002/recl.19770961004

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe reaction of 1,4‐dithiin (1) withn‐butyllithium has been examined. At −110° in tetra‐hydrofuran 2‐lithio‐1,4‐dithiin (2) is sufficiently stable to allow of the preparation of derivatives. Anion (2) undergoes ring opening by a 1,2‐elimination at −60°; subsequent methylation and hydrolytic work‐up gives ZHC≡CS‐CHCHSMe (6), or Z−MeC≡C−S−CHCH−SMe (7). At about −5° butyllithium attacks sulfur in the intermediary Z−LiC≡C−S−CHCH−SLi (4), leading to Z−BuS−CHCH−SLi (8), and LiC≡CLi.These results are not in agreement with the mechanism proposed byParhamet al. for benzo‐1,4‐dithiin and 2,5‐diphenyl‐1,4‐dithiin. We studied also the reactivity of 2,6‐dimethyl‐1,4‐dithiin (13), and 2,6‐ di‐tert‐butyl‐1,4‐dithiin (25), towards butyllithium. Starting from13the otherwise, difficultly accessible tri‐ and tetramethyl‐1,4‐dithiins could be prepared in high yield.The ring opening provides a valuable method for the synthesis of

ISSN:0165-0513    

DOI:10.1002/recl.19770961005

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractReaction of N‐(4‐toluenesulfonyl)dithiocarbamic acid with methylene iodide, in the presence of base in DMSO solution has not yielded the expected (4‐toluenesulfonyl)‐1,3‐dithietane. Instead in low yield 3‐(4‐toluenesulfonyl)‐2‐(4‐toluenesulfonylimino)‐1,3‐thiazetidine has been isolated. The structure of the compound is deduced from elemental analysis and spectral data and confirm

ISSN:0165-0513    

DOI:10.1002/recl.19770961006

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

Abstract10‐Aryl‐9‐arsaanthracenes (3b,c,d) were conveniently synthesized by flash vacuum pyrolysis at ∼ 500° of 10‐mono‐ and di‐substituted 9‐aryl‐9,10‐dihydro‐9‐arsaanthracenes (11a‐f). The yield of 10‐aryl‐9‐arsaanthracenes is found to depend upon the substituents at C(10). The occurrence of radical in

ISSN:0165-0513    

DOI:10.1002/recl.19770961007

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe synthesis of three 9,11‐dideoxyprostaglandins in which the cyclopentane moiety is replaced by a six‐membered ring, is described. Starting from phthalaldehydic acid (1) the aromatic PG‐analogue, 7‐[2‐(3‐hydroxy‐(E)‐1‐octenyl)phenyl]heptanoic acid (9), was prepared in 7 steps in 49% overall yield. Thecis‐substituted cyclohexane PG‐analogue, ethyl 7‐[cis‐2‐(3‐hydroxy‐(E)‐1‐octenyl)cyclohexyl]heptanoate (34), was obtained in 7 steps in 53% overall yield from the same starting material1. Thetrans‐substituted cyclohexane PG‐analogue, ethyl 7‐[trans‐2‐(3‐hydroxy‐(E)‐1‐octenyl)cyclohexyl]heptanoate (20), was synthesized from methyl

ISSN:0165-0513    

DOI:10.1002/recl.19770961008

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractUnder the influence of boron trifluoride quinoid γ‐oxo‐α,β‐unsaturated thiolesters (5) and (10) rearrange into α‐alkylthio‐γ‐lactones (6) and (9), respectively, in yields of 50–90%. In the case ofS‐alkyl 2‐(10‐oxo‐9‐phenanthrenylidene)alkanethioates (13) decarbonylation occurs with formation of α,β‐unsaturated ketones (14). Mechanisms are proposed. The γ‐oxo‐α,β‐unsaturated thiolesters were preparedin situfrom a 1‐alkynyl sulfide and 3,5‐di‐tert‐butyl‐o‐benzoquinone or 9,10‐phen

ISSN:0165-0513    

DOI:10.1002/recl.19770961009

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19770961001

出版商:WILEY‐VCH Verlag    

年代:1977

数据来源: WILEY