Premium
Photocyclodimerization of 5‐Methyl‐2 H ‐pyran‐3(6 H )‐one
Author(s) -
Groesch Ljubov,
Kopf Jürgen,
Margaretha Paul
Publication year - 2008
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200890239
Subject(s) - chemistry , cyclobutane , pyran , structural isomer , stereochemistry , isophorone , crystallography , ring (chemistry) , organic chemistry , catalysis
The structures of the main products resulting from photocyclodimerization of the title compound 2 and of other 3‐methyl‐substituted ‘oxacyclohex‐2‐en‐1‐ones’ (=dihydropyranones) were determined by X‐ray crystallography. In connection, the 13 C‐NMR chemical shifts of the cyclobutane C‐atoms of these dimers allow a clear differentiation between head‐to‐head and head‐to‐tail regioisomers, all structurally related to those of isophorone ( 1 ).