4988-33-4

Upstream product

• 7647-01-0 hydrogenchloride 
• 17396-35-9 1,1-dioxotetrahydrothiopyran-4-one 
• 314056-83-2 (but-3-ene-1-sulfonylmethylselanyl)-benzene 
• 197148-70-2 hex-5-enoic acid 2-thioxo-2H-pyridin-1-yl ester 

Downstream Products

• 63149-24-6 4-(1,1,2-trimethyl-1H-benzo[e]indol-3-ium-3-yl)butane-1-sulfonate 
• 1220981-52-1 N-[1-(tetrahydro-1,1-dioxido-2H-thiopyran-2(S)-yl)cyclohexyl]-2-methyl-2-propane-(S)-sulfinamide 
• 1220981-53-2 N-[1-(tetrahydro-1,1-dioxido-2H-thiopyran-2(R)-yl)cyclohexyl]-2-methyl-2-propane-(S)-sulfinamide 
• 14856-64-5 2-phenyltetrahydro-2H-thiopyran 1,1-dioxide 

Relevant academic research and scientific papers

Radical [n + 1] annulations with sulfur dioxide

A new methodology for [n + 1] radical annulation using sulfur dioxide as a geminal radical acceptor/donor is presented. This methodology provides a novel route to the formation of five-, six-, and seven-membered cyclic sulfones utilizing a radical chain m

The regiochemistry of cyclization of α-sulfenyl-, α-sulfinyl-, and α-sulfonyl-5-hexenyl radicals: Procedures leading to regioselective syntheses of cyclic sulfones and sulfoxides

A study of the cyclization of α-sulfenyl-, α-sulfinyl-, and α-sulfonyl-5-hexenyl and 5-methyl-5-hexenyl radicals reveals a unique contrast in the mode of ring closure of the radicals. In the case of the 5-hexenyl radicals, the sulfinyl-substituted species displays unexpected regioselectivity relative to its analogues. Thus, while the α-S- and α-SO2-5-hexenyl radicals give measurable and increasing quantities of 6-endo product, the α-sulfinyl species cyclizes with high selectivity (95.5:4.5) via a 5-exo mode. By contrast, ring closure of the 5-methyl-5-hexenyl radicals is found to give substantially the 6-endo product in all cases. It is the α-sulfonyl-5-methyl-5-hexenyl radical that now exhibits high regioselectivity (97.5:2.5) for 6-endo closure: an illustration of the synthetic value of this observation is the independent synthesis of the model cyclohexyl sulfone 61 in high yield. It is found that ring closure under the conditions employed occurs irreversibly in all cases.

Ring closure of 2-thia- and 2-sulfonyl-5-hexenyl radicals

Reductive cyclisation of the 2-sulfonyl-5-hexenyl radical with tributyltin hydride in benzene at 80°C affords a 73:23 mixture of the sulfones derived from 5-exo- and 6-endo- ring closure with a small quantity (4%) of reduced material; under identical conditions, the 2-thia-5-hexenyl radical gives a 70:13:17 mixture of the corresponding sulfides. (C) 2000 Elsevier Science Ltd.

Regioselectivity in the formation of cyclic sulphones from 4- and 5-alkenesulphonyl chlorides

Alk-4-enesulphonyl chlorides and alk-5-enesulphonyl chlorides cyclise under free radical conditions mainly in the endo mode to give tetrahydrothiopyran-1,1-dioxide and thiepane-1,1-dioxide respectively.