... Page 6. 64 HELVETICA CHIMICA ACTA -Vol. 81 (1998) 1389m. ... The m~xture is filtered over Celite, the filtrate acidified by addition of 10% aq. citric acid soin. and diluted with an equal volume of AcOEt, and the org. ... Page 7. HtLVETICA CHIMICA ACTA - Vol. 81 (1998) 65 ...