Triethylamine → HCID 6455298, compound

Participants

Reaction Steps

To a solution of monic acid (2.064 g; 6 mM) and triethylamine (0.840 ml; 6 mM) in dry tetrahydrofuran (50 ml) was added diethyl phosphorochloridate (1.035 g; 6 mM), at room temperature under an argon atmosphere. The mixture was stirred at room temperature for three hours and the precipitated triethylamine hydrochloride was removed by filtration. The solid was washed with tetrahydrofuran and to the combined filtrate and washings was added thallium (I) methanethiolate (1.506 g; 6 mM). The resulting suspension was stirred at room temperature for sixteen hours and then filtered through a celite plug. The solvent was removed at reduced pressure and the residue partitioned between ethyl acetate and sodium bicarbonate solution. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulphate. Removal of the solvent at reduced pressure gave the crude thiol ester as a colourless oil. This oil was purified by column chromatography over silica gel (Type 60; 25 g). Elution with 5% methanol/chloroform afforded the pure methanethiol ester of monic acid A as a colourless oil, which crystallised with ether (1.10 g; 49%). M.pt. 74°-75° C. (ether). (Found: C, 58.0; H, 8.1; S, 8.8 C18H30SO6 requires: C, 57.7; H, 8.1; S, 8.6%), [α]D20 -9.25° (c 1.0 CHCl3), λmax (EtOH) 237 nm (εm 12,100), 268 nm (εm 10,300), νmax (CHBr3) 3440, 1660 and 1620 cm-1, δH (CDCl3) 6.01 (1H, s, CH=C); 2.28 (3H, s, --SCH3); 2.17 (3H, s, CH3 --15); 1.20 (3H, d, J=6.5 Hz, CH3 --14); 0.91 (3H, d, J=6.0 Hz, CH3 --17), δc (CDCl3) 190.0, 154.0, 124.4, 75.0, 70.9, 70.4, 68.9, 65.4, 61.1, 55.7, 42.7, 39.7, 31.6, 20.6, 20.1, 12.5, 11.5, m/e 327.1812 (C17H27O6 requires 327.1808; 10%), 227 (20%), 169 (10%), 141 (23%), 111 (100%), no M+.

Provenance & Evidence