Premium
Reactions of 4‐Oxoalkanoic Acids, 4. Synthesis of (±)‐6‐Alkyl‐5‐oxa‐1‐azabicyclo[4.3.0]nonan‐9‐ones, (±)‐5‐Alkyl‐4‐oxa‐1‐azabicyclo[3.3.0]octan‐8‐ones, and Substituted 1,6‐Dioxa‐3,8‐diazacyclodecanes by Reaction of Ethyl 4‐Oxoalkanoates with 3‐Aminopropanol and 2‐Aminoethanol
Author(s) -
Wedler Christine,
Schick Hans,
ScharfenbergPfeiffer Doris,
Reck Günter
Publication year - 1992
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199219920107
Subject(s) - alkyl , chemistry , molecular sieve , yield (engineering) , bicyclic molecule , methanol , stereochemistry , medicinal chemistry , organic chemistry , catalysis , materials science , metallurgy
Ethyl 4‐oxoalkanoates 1 react at ambient temperature in dry methanol in the presence of molecular sieve 3 Å in almost quantitative yield with 3‐aminopropanol and 2‐aminoethanol to form the bicyclic lactams rac ‐ 2 and rac ‐ 3 , respectively. Surprisingly, the (±)‐5‐alkyl‐4‐oxa‐1‐azabicyclo[3.3.0]octan‐8‐ones rac ‐ 3a – d dimerize in trichloromethane saturated with 2 N HCl to the ten‐membered heterocycles 4a – d . The structures of the substituted 1,6‐dioxa‐3,8‐diazacyclodecanes 4a and 4c have been determined by an X‐ray crystal analysis.