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A Horner‐Emmons Approach to Cumulatrienes
Author(s) -
Macomber Roger S.,
Hemling Thomas C.
Publication year - 1985
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.198500083
Subject(s) - chemistry , carbanion , adduct , triphenylphosphine , rhodium , medicinal chemistry , stereochemistry , organic chemistry , catalysis
Reaction of allenic phosphonates of structure (R'O) 2 P(O)CH′CCR 2 with LDA led to ylid‐like carbanions ( 2 ) by removal of H′. Intermediate 2 reacted with a variety of ketones (R′ 2 ′CO) to give adducts ( 3 ) which fragmented to cumulatrienes of structure R′ 2 CCCCR 2 . The cumulatrienes prepared and their yields were: 4a (RCH 3 , R′Ph, 43%); 4b (R+RR′+R′(CH 2 ) 5 , 64%); 4c (R+R(CH 2 ) 5 , R′Ph, 28%); 4d (RR′CH 3 , 23%). In two cases, 4a and 4d , the cumulatrienes were complexed with chlorotris (triphenylphosphine)‐rhodium.