ring closure sentence in Hindi

Examples

1. The ring closure is carried out at high temperatures ( 200 300 �C, 473 573 K ).
2. A rearrangement reaction of the carbocation follows with ring closure to "'9 " '.
3. In addition, the electronic structure of the transition state differs from that of other conrotary ring closures.
4. It was proposed that the methylene of ( + )-Costunolide is reduced before the second ring closure.
5. For this step, the Schiff base must be heated to ~ 250 �C for the ring closure to occur.
6. The ring closure can even be driven by stereocenters adjacent to the carbon-carbon multiple bond as shown below.
7. Subsequent ring closure leads to the formation of the ?-lactam and the regeneration of the chiral nucleophilic organocatalyst.
8. The mechanism of ring closure is complex, but involves an aldol condensation at C-2 and C-7.
9. This allows for strictosidine s formation under the subsequent ring closure via electrophilic substitution, as shown in the adjacent image.
10. Compound XII was formed from condensation of [ carbonyl-14C-]-2-hydroxy-acetophenone with dimethyl oxylate and ring closure.