[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([CH3:8])[C:3]=1[S:9](Cl)(=[O:11])=[O:10].[CH2:13]([P:16](=[O:22])([CH2:19][CH2:20][CH3:21])[CH2:17][OH:18])[CH2:14][CH3:15].C(N(CC)CC)C>C1COCC1.C(Cl)Cl.C(OCC)(=O)C>[CH2:13]([P:16](=[O:22])([CH2:19][CH2:20][CH3:21])[CH2:17][O:18][S:9]([C:3]1[C:4]([CH3:8])=[CH:5][CH:6]=[CH:7][C:2]=1[Cl:1])(=[O:10])=[O:11])[CH2:14][CH3:15]A solution of 7.20 g of 2-chloro-6-methylbenzenesulfonyl chloride dissolved in 30 ml of THF was added dropwise over 30 minutes to a reaction mixture 5.80 g of di-n-propyl(hydroxymethyl)-phosphine oxide, (Example 23), 30 ml of THF, and 4.04 g of triethylamine. The addition caused a mild exotherm and the reaction was allowed to stir at room temperature over the weekend. Most of the THF was removed and the resulting material was partitioned between 200 ml of ethyl acetate and 70 ml of water, the organic phase rewashed with an additional 70 ml of water, dried with magnesium sulfate, filtered and concentrated to yield 6.5 g of the crude desired product as a dark tan oil. The crude product was diluted with 4 ml of methylene chloride and flash chromatographed on Merck silica gel (230-400 mesh) using blends of isopropanol and ethyl acetate, similar fractions were combined and concentrated under reduced pressure to yield the partially purified product. This material was dissolved in 150 ml of ethyl acetate, washed with three 50 ml portions of water, dried with magnesium sulfate, filtered and concentrated to yield 2.4 g of the desired product as a white solid: melting point 51°-53° C.
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