Zur Reaktion von Dialkylphosphiten mit α-Enonen, II. 2:1-Addukte aus Dimethylphosphit und α-Enonen: Darstellung von (1-Hydroxy-1,3-alkandiyl)diphosphonaten und 5-Dimethoxyphosphoryl-2-methoxy-1,2-oxaphospholan-P-oxiden
✍ Scribed by Öhler, Elisabeth ;Zbiral, Erich
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 854 KB
- Volume
- 1991
- Category
- Article
- ISSN
- 0947-3440
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✦ Synopsis
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 NaOCH~3~‐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).