Elisabeth Öhler, E. Zbiral
Mar 12, 1991
Citations
0
Influential Citations
11
Citations
Journal
European Journal of Organic Chemistry
Abstract
Reaction of Dialkyl Phosphites with α-Enones, II. – 2:1 Adducts from Dimethyl Phosphite and α-Enones: Synthesis of (1-Hydroxy-1,3-alkanediyl)diphosphonates and 5-Dimethoxyphosphoryl-2-methoxy-1,2-oxaphospholane P-Oxides On NaOCH3-catalyzed reaction with two equivalents of dimethyl phosphite (2), various α-enones 1 are transformed into the diphosphonates 5 (e.g. 5a, 5b, 5e, 5f), which, depending on the structure of the enone, can further react with ring closure to give the 1,2-oxaphospholanes 6 (e.g. 6c, 6g, 6h), or with phosphonate-phosphate rearrangement of the α-hydroxyphosphonate moiety to yield compounds 7 (e.g. 7d). The formation of the 2:1 adducts is believed to occur via addition of 2 to the carbonyl group of the (3-oxoalkyl)phosphonates 4, formed from thermodynamically controlled 1,4 addition of 2 to 1. Compounds 4 could also be treated with 2 to yield 2:1 adducts (e.g. 4c 5c, 4d 5d, 4d 7d).