成人免费xx,国产又黄又湿又刺激不卡网站,成人性视频app菠萝网站,色天天天天

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List (R)-(+)-Tetrahydro-2-furoic acid
87392-05-0

(R)-(+)-Tetrahydro-2-furoic acid synthesis

8synthesis methods
-

Yield:87392-05-0 9.339 g

Reaction Conditions:

with L-Phenylalaninol in ethyl acetate;acetone at 20; for 1 h;

Steps:

7; 9 Example 7:

Add L-phenylalaninol resolving agent (10g, 66mmol, 99% ee) to a 1000mL three-neck reaction flask and330 mL of acetone,After stirring and dissolving the dissolving agent,A mixture of 110 mL of ethyl acetate and (RS)-THFA (11.6 g, 100 mmol) was added.The reaction was mechanically stirred at 20 ° C for 1 h.A white solid precipitated, which was quickly filtered and weighed 7.536 g of diastereomer salt.The obtained diastereomer salt is recrystallized from acetone, first heated to about 56 ° C, to obtain a clear transparent liquid, stop heating, slowly cool naturally and stir at low speed until the temperature drops to 20 ° C, constant temperature and low speed stirring and crystallization for 1 h. Filtration, filter cake dissolved in 5mol / L sulfuric acid aqueous solution and adjusted to pH <2, adding DCM (3 × 100mL) extraction layering, liquid separation to obtain the first aqueous phase a1 and the first organic phase, combined with the first organic extract phase,Then dried over anhydrous Na2SO4, and concentrated to recover the solvent (S) -2-THFA (1.853g),99.71% ee, yield was 32%.The primary mother liquor and the recrystallization mother liquor obtained by the above filtration are combined, the solvent is distilled off, the distillation residue is fully dissolved with 5 mol/L sulfuric acid aqueous solution and adjusted to pH<2, and DCM (4×100 mL) is added for extraction and layering, and liquid separation is obtained. secondThe aqueous phase a2 and the second organic phase are combined with the extracted second organic phase,Then dried with anhydrous Na2SO4,The solvent (R)-2-THFA (9.339 g) was recovered by concentration.21.3% ee.

References:

CN109705064,2019,A Location in patent:Paragraph 0026; 0030; 0031

(R)-(+)-Tetrahydro-2-furoic acid Related Search: