Synthesis of 2‐phosphoro‐1,2‐thiazetidine 1,1‐dioxide

The reactions of phosphorochloridites 5a–c with an equimolar amount of 1,2‐thiazetidine 1,1‐dioxide (2) or L(?)‐3‐carboethoxy‐1,2‐thiazetidine 1,1‐dioxide (7) in the presence of triethylamine, affords the N‐phosphitylated β‐sultams 6a–b and L(?)‐8a,c. Their oxidation by addition of oxygen, sulfur, or selenium results in formation of stable organophosphorus β‐sultams 10a–b, L(?)‐11a,c, 12a, 13a, L(?)‐14c, and L(?)‐15c. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 61–67, 1999