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Cycloadditions, 53. New spirocyclic chiral dienes — synthesis and diastereoselective Diels‐Alder reactions with N ‐phenylmaleimide
Author(s) -
Hoffmann Ralf,
Mattay Jochen
Publication year - 1995
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.1995199508198
Subject(s) - chemistry , diketene , menthone , diastereomer , organic chemistry , diels–alder reaction , adduct , chiral auxiliary , enantioselective synthesis , menthol , catalysis
Synthesis and diastereoselective Diels‐Alder reactions of new spirocyclic chiral dienes are reported. Starting with diketene and (−)‐menthone ( 1 ), we prepared the diastereomeric diketene‐menthone adducts 2 and 3 . Further derivatization and olefination afforded four chiral dienes 12 ‐ 15 . Diastereoselective Diels‐Alder reactions of these dienes with N ‐phenylmaleimide (NPM) under high‐pressure conditions yielded the corresponding cycloadducts 16 ‐ 19 . Olefination of 6‐diethylphosphonomethyl‐2,2‐dimethyl‐1,3‐dioxin‐4‐one 8 with formaldehyde led to unexpected compounds 9 ‐ 11 resulting from the originally formed olefination product.