Teenage boy transported to Medieval Ukraine

Question

I read this in the late 1990s. A teenage boy in New York is transported (possibly by entering something like an Anderson shelter) to the middle of the woods in what turns out to be medieval Ukraine.

He notices a disturbance in the leaves and begins walking in a circle, the disturbance follows him and this causes the leaves to blow away, revealing a bear stalking him (walking upright) at the bottom of a circular ditch -- the boy has been standing on a hill in the middle of the circle. For some reason the bear goes away when revealed.

Later a girl shows up and helps him across the ditch. He begs her for an article of clothing to cover himself, and she's shocked that he would wear a woman's garment even in such a circumstance, but she lends him her "hoose" (which I think is some sort of scarf).

The girl takes the boy to her village. The villagers deride him for wearing the hoose and also because of how skinny he is -- they call him "stick-man" because he isn't "muscled like Alley Oop" the way the other village men are.

Several legendary Ukrainian figures like Baba Yaga and the Firebird make their appearance -- in fact the boy defeats Baba Yaga (who is given an Elphaba-like backstory but needs to be defeated all the same) and saves the villagers.

The boy is able to travel back to modern New York but has a new appreciation for his Ukrainian heritage and soon moves to Ukraine.

Answer 1

Sounds like Enchantment, by Orson Scott Card.

The protagonist and narrator is Ivan Smetski, a young Ukrainian-American linguist who specializes in Old Church Slavonic, a language from 10th-century Ruthenia. In 1992, Ivan returns to his native town of Kyiv to pursue additional graduate studies. While there he re-discovers the body of a woman that he had seen as a child, apparently sleeping in the woods. He awakens her with a kiss, and she tells him, in Old Church Slavonic, that she is Katerina, a princess of the kingdom of Taina.

• From Wikipedia.

The boy is able to travel back to modern New York but has a new appreciation for his Ukrainian heritage and soon moves to Ukraine.

His name is Ivan, and the book implies he is the source of all of the Clever Ivan Fairy tales. He doesn't move to present day Ukraine, but rather spends half of his time in past Ukraine/half in the modern era

Several legendary Ukrainian figures like Baba Yaga and the Firebird make their appearance

I don't remember a firebird, but Baba Yaga steals a 747 from the future and takes it into the past. Which later becomes Baba Yaga's Three legged chicken house that could move/fly in the fairy tales.

-- in fact the boy defeats Baba Yaga (who is given an Elphaba-like backstory but needs to be defeated all the same) and saves the villagers

Baba Yaga is there, and is in conflict with them. While her backstory is flushed out... I didn't think her backstory was particularly redeeming. Katerina is the one who ultimately defeats Baba Yaga, not Ivan.